Fix handler-source and component-source lookups

Both used (env-get name) with one arg which always returned nil.
Now use eval-expr + make-symbol with cek-try fallback, same pattern
as the handler dispatch.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

sx/sx/data/helpers.sx

@@ -3,7 +3,7 @@
   (fn
     (name)
     (let
-      ((val (env-get name)))
+      ((val (cek-try (fn () (eval-expr (make-symbol name))) (fn (err) nil))))
       (if
         (or (component? val) (island? val))
         (let
@@ -24,11 +24,15 @@
   (fn
     (name)
     (let
-      ((val (env-get name)))
+      ((handler-key (str "handler:" name))
+        (val
+          (cek-try
+            (fn () (eval-expr (make-symbol handler-key)))
+            (fn (err) nil))))
       (if
         (not (nil? val))
         (pretty-print val)
-        (error (str "Handler not found: " name))))))
+        (str ";;; Handler not found: " name)))))
 
 (define _spec-dirs (list "spec" "web" "shared/sx/ref" "lib"))